Tool operating mechanism



Sept. 25, 1956 O. A. WANDEL TOOL OPERATING MECHNISM` Filed Sept. 17, 1953 United States Patent O TOOL OPERATING MECHANISM Oscar A. Wandel, Chicago, lll., assignor to Fastener Corporation, Chicago, Ill., a corporation of Illinois Application September 17, 1953, Serial No. 380,761

1 Claim. (Cl. 1-44.4)

This invention relates to power tools and is more particularly concerned with improvements in a tool of the type generally employed for driving various kinds of fasteners or similar elements.

It is a general object of the invention to provide in a tool of the type wherein an element, such as a fastener, is driven by a blow from a reciprocating blade, a mechanism responsive to pressure on the tool, when the tool is positioned against the object into which the element is to be driven, for actuating the blade to perform the driving operation.

It is another object of the invention to provide a mechanism for incorporation in a power operated element driving tool, which mechanism is operative to automatically actuate the tool, upon pressure being applied thereto with the tool in position for the driving operation.

It is a more specic object of the invention to provide, in a pneumatic stapler or tacker having an operating fluid control valve, a control mechanism for the valve which comprises a handle member and a linkage arrangement for movably connecting the same to the frame of the stapler, the linkage arrangement having a valve actuating element, and the valve being actuated upon suficient pressure being applied to the handle to move the same in the direction of the tool with the tool properly positioned relative to the work piece for the driving of the staple.

It is a further object of the invention to provide an operating mechanism for a pneumatic tacker having a reciprocable air control valve element, which mechanism comprises a handle member and a mounting frame for supporting the same on the tacker, which frame includes a pivoted arm operative to actuate the air valve upon movement of the handle mounting frame, which occurs when pressure is applied to the handle member and the tacker is restrained against movement.

These and other objects and advantages of the invention will be apparent from a consideration of the mechanism which is shown by way of illustration in the accompanying drawings, wherein:

Fig. l is a side elevation of a pneumatic tool having incorporated therein the principal features of the invention;

Fig. 2 is a top plan view of the tool;

Fig. 3 is a cross section, to an enlarged scale, taken on the line 3-3 of F ig. l;

Fig. 4 is a cross section taken on the line 4--4 of Fig. 3, with portions broken away.

In the form of the invention which is illustrated in the drawings the operating mechanism is incorporated in a pneumatically operated fastener driving device which is generally referred to as an air driven tacker. The tacker comprises a body frame 11 having, at the forward end thereof, a hollow head portion forming `a vertically eX- tending cylindrical chamber 12 which is connected by the air passage 13 and the valve mechanism 14 with an air chamber 15, the latter extending generally horizontally of the upper or main portion of the body frame 11. Air

or other operating fluid is supplied to the compartment or chamber 15 by a suitable air hose connection 16 from an air supply line or other source (not shown). Passage of the operating fluid from the compartment 15 to the .chamber 12 is controlled by operation of the valve mechanism 14.

A reciprocating piston 17 is mounted in the cylindrical chamber 12 and carries a depending fastener driving blade 18. The piston 17 is urged in the upward direction by a compression spring 19 towards a cap 20 which is connected in screw threaded relation on the upper end of the hollow barrel-like member forming the chamber 12 and which functions as a closure for the same. A guideway forming member 21 for the driving blade 18 is provided at the lower end or terminus of the chamber 12 and at the forward end of a magazine 22 which contains a supply of staples 23 or other fastening elements.

The magazine l22 is of conventional construction with an outer casing 24 having a longitudinally extending fastener supporting central rib 25 on which the staples 23 are positioned and a removable cover member 26 which carries a inverted U-shaped pusher 27 adapted to straddle the rib 25 and a suitable actuating tension spring arrangement 28 which urges the pusher 27 in the direction of the guideway forming member 21. The cover member 26 is of inverted U-shaped cross section and is retained in closed position with its side walls extending downwardly into the outer casing 24 by a leaf spring 29 which is secured on the top wall thereof at 30 and engages at its free end the inverted U-shaped bracket 31, the latter having its leg portions attached to the casing 24 and having its upper or cross web portion secured to the rearmost portion of the main frame 11 of the tool.

The control valve 14 is of conventional construction including a reciprocating stem 32 which projects from the valve chamber and is adapted to be operated in -a manner which will be described. The valve 14 allows the operating fluid to pass from the chamber 15 to the passageway 13 and through the passageway 13 to the top of the chamber 12 for operation of the piston 17 and blade 18, the return stroke of the piston 17 being effected by the spring 19 with suitable provision through passageway 13 and valve 14 for exhausting the uid during the return stroke. Repeated operation of the valve 14 supplies air to the chamber 12 and reciprocates the piston 17 to drive successive staples 23 fed from magazine 22.

The mechanism for operating valve 14 comprising an elongate handle member 33 which is positioned above the body 11 of the tool with the forward end extending over the cap member 20 and which is urged in the upward direction by a compression spring 34 which engages the cap 20 at one end and is seated in a shallow recess 3S in the bottom face of the handle member 33. At its forward end the handle 33 has secured on its lower face, by means of the rivet 36, a U-shaped strap 37 which depends therefrom and straddles the forward portion of the frame 11 with the leg portions 38 parallel to the cylindrical chamber 12 and extending to a point forwardly of the valve 14 where each leg 38 is pivotally connected at 39 with a forwardly extending arm member 40. The two arm members 40 which form the valve actuating device are pivotally mounted at 41 on the frame 11. A sm'all cross shaft 42 extends between the arm members 40 at a point spaced from the supporting pivot 41, and carries a cam roller 43 which is positioned to engage the bottom or projecting portion of the valve stem 32 so that upon movement of the connected arm members 40 in the counterclockwise direction about the pivot 41 the valve stem 32 is forced upwardly to open the valve and Iallow the air to reach the piston 17 for driving the fastener element 23.

The handle member 33 is connected adjacent its lower yreawend by-pivot 144 with :a pair of link members 45 which extend to a point beneath and to the rear of the 'air chamber 15 where they are Pivo-tally connectedby cross pin 46 with the upstanding flanges 47 of a bracket .member ,4,8 which is secured .to the .body ..11 byhav.iu g the end .thereofsuitabl-y apertured f o't over ,the fixture for the hose ,connection 16, with a. portion vofthe latter holding it `clamped.against .the body 11.

In operatingthe device allthatis required is to place the nose 49 of the tool against the work piece to which .thestaple or .other fastener is to be applied and to apply suicient pressure -on .the .handle 33 to overcome the force of the spring.34.and to pivot the cam roller '.43 suiciently to .actuate the valve 14 and effect the .driving .of .the 4fastener .23 in the mannerdescribed.

While the actuating .mechanismis 'illustrated as employed in .connection with .a pneumatic vor Yair driven fastener applying device it .may be also employed in .other tools of a similar .nature where the .tool -is posi- .power to the tool.

While specific details of constructionhave been referred to vin describing the illustrated .forni Y-of kvthe invention it will be understood that other detailsof con- .struction may .be resorted to within the spirit of the invention.

I claim:

.In a fastener driving tool, a body frame having a cylinder ,in the forward portion thereof which terminates at'a work engagingnose, .and a fluid drivenplunger having its lower end positioned-'todrive afastener through 4saidfnose, a'valveiorfcontrolling the passage of iluidto the cylinder for driving the plunger, and an operating mechanism for said valve, `said operating "mechanism comprising a handle member arranged in spaced relation above the body frame of said tool, a link pivotally connected at one end to the rear end of such member and at the other end to a rear portion of the frame of said tool, said link permitting limited vertical movement of said handle member relative to the forward portion of said body frame, a verticalbar .dependingffrom the forward .portion of said handle member and movable in the same direction as said plungena cam ,arm pivoted to said frame adjacent sai'd valve, said cam arm being pivotally ,connected tosaid depending `bar and `having a valve operating .member in spaced relation to the pivotal connections with'said frame and said depending bar and contacting the valve, whereby when said handle is moved by a force applied thereto in the direction of said frame and of the movementof said plunger said valve is actuatedto `permitthepassage of liquid to said cylinder for driving said plunger and said nose is urged into engagement-with the work, and spring means between the forward portion of said handle andthe forward portion of said frame for automatically returning said handle to a non-operating position upon said force being removed therefrom.

References Cited in the ile of this patent UNITED STATES PATENTS 562,518 vFerguson June 23, 1896 1,598,426 Ditson Aug. 31, 1926 1,719,143 Slater July 2, 1929 FOREIGN PATENTS 369,499 Germania- 1 Mar. 1.5, v1922 

